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2014

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Analysis Of The Influence Of Organic Corrosion Inhibitors On Corrosion Of Reinforcement In Concrete Bridge Structure Under Simulated Field Service Environment, Liang Shi, J. Ye, C. C. Chen, Y. Wu, J. Z. Liu Jan 2014

Analysis Of The Influence Of Organic Corrosion Inhibitors On Corrosion Of Reinforcement In Concrete Bridge Structure Under Simulated Field Service Environment, Liang Shi, J. Ye, C. C. Chen, Y. Wu, J. Z. Liu

International Conference on Durability of Concrete Structures

For concrete bridge projects in marine environments, attention must be paid to the reinforcement corrosion problems caused by chloride intrusion. As kinds of functional admixtures, which can reduce the reinforcement corrosion rate, corrosion inhibitors are becoming very popular in China in new bridge projects. Corrosion inhibitors cover both inorganic and organic inhibitors. Nitrite is representative of inorganic corrosion inhibitors, but its carcinogenicity has hindered its further development. Organic corrosion inhibitors such as small-molecule-based alcohol amine series are becoming the focus of attention. To guide the scientific applications of organic corrosion inhibitors, China is carrying out broad applications technology research. But …

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Cognitive Challenges To Resilience Dynamics In Managing Large- Scale Event Response, Barrett S. Caldwell Jan 2014

Cognitive Challenges To Resilience Dynamics In Managing Large- Scale Event Response, Barrett S. Caldwell

School of Industrial Engineering Faculty Publications

In early 2014, a number of large-scale adverse weather events in the United States (and elsewhere) have renewed discussions of event response and resilience. Unlike events caused by human error or malicious intent, adverse natural events can be seen as uncontrolled and unpreventable; the measure of response success is the mitigation of adverse and disastrous effects. However, significant cognitive limitations interfere with human decision makers’ ability to effectively estimate likelihood, magnitude, and effective response of large-scale events in the face of multiple forms of uncertainty and system dependencies. Some authors highlight stability and maintenance of original design capability as …

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An Animation Stimuli System For Research On Instructor Gestures In Education, Jian Cui, Voicu Popescu, Nicoletta Adamo-Villan, Susan Cook, Katherine Duggan, Howard Friedman Jan 2014

An Animation Stimuli System For Research On Instructor Gestures In Education, Jian Cui, Voicu Popescu, Nicoletta Adamo-Villan, Susan Cook, Katherine Duggan, Howard Friedman

Department of Computer Science Technical Reports

No abstract provided.

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Principles Of Refrigerant Circuit Optimization In Single Row Microchannel Condensers, Sunil Mehendale, Vikrant Aute, Reinhard Radermacher Jan 2014

Principles Of Refrigerant Circuit Optimization In Single Row Microchannel Condensers, Sunil Mehendale, Vikrant Aute, Reinhard Radermacher

International Refrigeration and Air Conditioning Conference

Automotive HVAC systems manufacturers were the first to introduce microchannel condensers in the comfort air-conditioning market. HVAC&R original equipment manufacturers have followed their lead and recently started using microchannel condensers in residential and commercial cooling and heat pump applications. These applications began less than a decade back and their number has been increasing steadily. The main difference between microchannel condensers used for the automotive and residential / commercial applications is that the latter span a much wider range of coil face areas compared to the former. Considering this fact, there are relatively few well-documented studies in the public domain on …

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Genomic Correlates Of Recombination Rate And Its Variability Across Eight Recombination Maps In The Western Honey Bee (Apis Mellifera L.), Caitlin R. Ross, Dominick S. Defelice, Greg J. Hunt, Kate E. Ihle, Gro Vang Amdam, Olav Rueppell Jan 2014

Genomic Correlates Of Recombination Rate And Its Variability Across Eight Recombination Maps In The Western Honey Bee (Apis Mellifera L.), Caitlin R. Ross, Dominick S. Defelice, Greg J. Hunt, Kate E. Ihle, Gro Vang Amdam, Olav Rueppell

Department of Entomology Faculty Publications

Background: Meiotic recombination has traditionally been explained based on the structural requirement to stabilize homologous chromosome pairs to ensure their proper meiotic segregation. Competing hypotheses seek to explain the emerging findings of significant heterogeneity in recombination rates within and between genomes, but intraspecific comparisons of genome-wide recombination patterns are rare. The honey bee (Apis mellifera) exhibits the highest rate of genomic recombination among multicellular animals with about five cross-over events per chromatid. Results: Here, we present a comparative analysis of recombination rates across eight genetic linkage maps of the honey bee genome to investigate which genomic sequence features are correlated …

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Non-Adiabatic Capillary Tubes In Cycle Simulations, Martin Heimel, Erwin Berger, Stefan Posch, Martin Eichinger, Raimund Almbauer Jan 2014

Non-Adiabatic Capillary Tubes In Cycle Simulations, Martin Heimel, Erwin Berger, Stefan Posch, Martin Eichinger, Raimund Almbauer

International Refrigeration and Air Conditioning Conference

Capillary tubes including a suction line heat exchanger are typical expansion devices used in nowadays domestic refrigeration appliances. To account for their functionality in transient cycle simulations, including the highly transient start-up and shut-down operations, different capillary tube models and their implementation in such a cycle are investigated. These non-adiabatic capillary tube models comprise dimensionless correlations, neural network methods and one-dimensional homogeneous models which stem partly from open literature and from previous work of the authors. The difficulty in application of capillary models during off-design conditions is when two phase flow or even superheated vapor which enters the capillary tube. …

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Using Surface Wettability To Impact The Frost Properties And Defrosting Effectiveness Of A Metallic Heat Transfer Surface, Nicholas Truster, Catherine Puleo, Edgar Caraballo, Andrew Sommers Jan 2014

Using Surface Wettability To Impact The Frost Properties And Defrosting Effectiveness Of A Metallic Heat Transfer Surface, Nicholas Truster, Catherine Puleo, Edgar Caraballo, Andrew Sommers

International Refrigeration and Air Conditioning Conference

In this work, the properties of a growing frost layer were analyzed for surfaces of varying wettability to determine the effect that the surface energy has on the frost mass, thickness, and density. Both patterned and non-patterned surfaces were explored. To date, three surfaces have been fabricated and tested— an uncoated, untreated aluminum plate (Sample 1), a plate coated with a super-hydrophobic coating (Sample 2), and a plate containing a triangular surface wettability pattern (Sample 3). For these experiments, the frost layer was grown for a three-hour period inside a Plexiglas environmental test chamber where the relative humidity was held …

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Development Of An Industrial High Temperature Heat Pump With Twin Screw Compressor, Yongning He, Dongfang Yang, Feng Cao, Gang Li Jan 2014

Development Of An Industrial High Temperature Heat Pump With Twin Screw Compressor, Yongning He, Dongfang Yang, Feng Cao, Gang Li

International Refrigeration and Air Conditioning Conference

In industrial applications, 90-150? hot water needed during production processes is traditionally provided by fuel-fired boilers. The usage of fuel-fired boiler has a low efficiency of energy use and potential danger of explosion. 30-60?waste water with large amount of energy is rejected to environment directly, which causes a great energy loss and thermal pollution. Seeking for a much high efficiency and safe heating pattern is essential to replace the boilers used now. High temperature heat pump is an ideal solution to recover the heat in waste water and to produce hot water needed. It has a higher efficiency than boilers …

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Associative Concept Learning In Animals, Thomas R. Zentall, Edward A. Wasserman, Peter J. Urcuioli Jan 2014

Associative Concept Learning In Animals, Thomas R. Zentall, Edward A. Wasserman, Peter J. Urcuioli

Department of Psychological Sciences Faculty Publications

Nonhuman animals show evidence for three types of concept learning: perceptual or similarity-based in which objects/stimuli are categorized based on physical similarity; relational in which one object/stimulus is categorized relative to another (e.g., same/different); and associative in which arbitrary stimuli become interchangeable with one another by virtue of a common association with another stimulus, outcome, or response. In this article, we focus on various methods for establishing associative concepts in nonhuman animals and evaluate data documenting the development of associative classes of stimuli. We also examine the nature of the common within-class representation of samples that have been associated with …

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Writing Lab Strategic Plan, Linda S. Bergmann, Tammy Conard-Salvo, Vicki Kennell Jan 2014

Writing Lab Strategic Plan, Linda S. Bergmann, Tammy Conard-Salvo, Vicki Kennell

Purdue Writing Lab/Purdue OWL Research Reports

The Purdue University Writing Lab and Purdue Online Writing Lab (OWL) assist clients in their development as writers—no matter what their skill level—with on-campus services, online participation, and community engagement. The Purdue Writing Lab serves the Purdue-West Lafayette campus and coordinates with local literacy initiatives, while the Purdue OWL offers global support through online reference materials and services.

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Mixed Lubrication Analysis Of Vane Sliding Surface In Rotary Compressor Mechanisms, Yasutaka Ito, Hitoshi Hattori, Kazuhiko Miura Jan 2014

Mixed Lubrication Analysis Of Vane Sliding Surface In Rotary Compressor Mechanisms, Yasutaka Ito, Hitoshi Hattori, Kazuhiko Miura

International Compressor Engineering Conference

In the compression mechanisms of a rotary compressor for air conditioners, a vane and a rolling piston are provided to separate the suction chamber and the compression chamber. The rolling piston is driven by the crank, and revolves on the axis of the shaft eccentrically, and also rotates on its own axis. The vane undergoes reciprocating motion, and its top usually comes into contact with the rolling piston by the spring force and the discharge pressure. The lubricating condition between the vane top and the rolling piston is severe because the contact pressure is high owing to the line contact …

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Simulation Study On The Performance Of An Injection Scroll Compressor In A Heat Pump For Electric Vehicles, Jongho Jung, Dongwoo Kim, Yongseok Jeon, Yongchan Kim Jan 2014

Simulation Study On The Performance Of An Injection Scroll Compressor In A Heat Pump For Electric Vehicles, Jongho Jung, Dongwoo Kim, Yongseok Jeon, Yongchan Kim

International Compressor Engineering Conference

This paper presents the development and validation of a simulation model of an injection scroll compressor that can be used for optimization of a heat pump system for electric vehicles. The modeling considered the effects of refrigerant leakage and suction gas heating. The simulation model solved continuity and energy conservation equations using 4th Runge-Kutta scheme to predict the pressure and temperature variations according to scroll revolution. The refrigerant mass flow rate, compressor discharge temperature, and compressor power input were calculated. The results of the simulation model were validated with the experimental data. The simulation model predicted the compressor performance within …

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Comprehensive Model Of A Single-Screw Expander For Orc-Systems, Davide Ziviani, Ian Bell, Martijn Van Den Broek, Michel De Paepe Jan 2014

Comprehensive Model Of A Single-Screw Expander For Orc-Systems, Davide Ziviani, Ian Bell, Martijn Van Den Broek, Michel De Paepe

International Compressor Engineering Conference

The Organic Rankine Cycle (ORC) system is considered one of the leading technologies for waste heat recovery applications. In order to increase the overall efficiency, design improvements and optimization analyses are necessary. The expander is the key component to convert the thermal energy in useful work. Several volumetric and turbine expanders have been investigated. Among volumetric machines, scroll, twin-screw and vane-type expanders are the main technologies. Recently, a number of experimental studies on single-screw expanders (SSE) have been carried out, demonstrating the feasibility of employing such machine as an ORC expander. The single screw configuration presents a number of advantages …

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Design Optimization Of The Suction Manifold Of A Reciprocating Compressor Using Sensitivity Analysis, Nasir Bilal Jan 2014

Design Optimization Of The Suction Manifold Of A Reciprocating Compressor Using Sensitivity Analysis, Nasir Bilal

International Compressor Engineering Conference

A new method for the design of the suction manifold of a reciprocating compressor using sensitivity and uncertainty methods was used. The objective was to pick the optimal values of the compressor suction manifold to minimize gas pulsations. The advantage of the method is that the input parameters do not have fixed values but a range is provided. Similarly, the output is specified in terms of a probability density function. Another advantage of this method is that we can set our limit on the maximum values of the gas pulsation that are permissible and then vary the input parameters so …

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Investigation Of Application Of Suction Line Heat Exchanger In R290 Air Conditioner With Small Diameter Copper Tube, Tao Ren, Guoming Wu, Guoliang Ding, Yongxin Zheng, Yifeng Gao, Song Ji Jan 2014

Investigation Of Application Of Suction Line Heat Exchanger In R290 Air Conditioner With Small Diameter Copper Tube, Tao Ren, Guoming Wu, Guoliang Ding, Yongxin Zheng, Yifeng Gao, Song Ji

International Refrigeration and Air Conditioning Conference

R290 is a potential refrigerant replacing R22 because of its zero Ozone Depletion Potential (ODP) and virtually zero Global Warming Potential (GWP). However, R290 is flammable and requires excellent containment to avoid leakage and reduce the risk of fire. The use of small diameter copper tube (5 mm or even smaller) is an effective way to reduce refrigerant charge and thus reduce the risk of fire in the event of a refrigerant leak. However, employing small diameter copper tube will increase pressure drop and consequently reduce system performance. A suction line heat exchanger which employs the low temperature refrigerant in …

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Experimental Study On Performance Of Two-Phase Ejector Refrigeration Cycle System With Two-Throat Nozzle, Li Qian Ren, Xian Min Guo, Xin Wei Guo, Tian Long Li Jan 2014

Experimental Study On Performance Of Two-Phase Ejector Refrigeration Cycle System With Two-Throat Nozzle, Li Qian Ren, Xian Min Guo, Xin Wei Guo, Tian Long Li

International Refrigeration and Air Conditioning Conference

The two-phase ejector refrigeration cycle (TPERC) system with a two-throat nozzle ejector was investigated experimentally, and the entrainment ratio of the ejector and the COP of the system were compared with those of the ejector with Laval nozzle and the TPERC system respectively. The experimental results indicate that the entrainment ratios of the two-throat nozzle ejectors with different geometric size are greater than those of the Laval nozzle ejectors under the working condition of the evaporating/condensing temperatures 1?/45?, the maximum increment of the entrainment ratio is about 18%, and the COP of the TPERC system with two-throat nozzle ejector is …

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Thermodynamic Analysis Of Adsorption Refrigeration Cycles Using Parent And Surface Treated Maxsorb Iii/Ethanol Pairs, Kutub Uddin, Ibrahim I. El-Sharkawy, Takahiko Miyazaki, Bidyut Baran Saha, Shigeru Koyama Jan 2014

Thermodynamic Analysis Of Adsorption Refrigeration Cycles Using Parent And Surface Treated Maxsorb Iii/Ethanol Pairs, Kutub Uddin, Ibrahim I. El-Sharkawy, Takahiko Miyazaki, Bidyut Baran Saha, Shigeru Koyama

International Refrigeration and Air Conditioning Conference

Adsorption equilibrium uptake of environment friendly refrigerant ethanol onto highly porous activated carbon based adsorbents has been experimentally investigated by using a magnetic suspension balance adsorption measurement unit (MSB-VG-S2). Adsorbents used in the present study are parent Maxsorb III, H2 and KOH-H2 surface treated Maxsorb III. Experiments have been conducted over adsorption temperatures range from 30 to 70 ºC and evaporation temperatures between -6 and 65 ºC. The Dubinin-Radushkevich and Dubinin-Astakhov adsorption isotherm models have been used to correlate adsorption isotherm data and to plot the pressure-temperature-concentration (P-T-W) diagrams of the assorted pairs. Isosteric heat of adsorption is estimated using …

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The Evaluation Method Of Hvac System’S Operation Performance Based On Energy Flow Analysis And Dea, Xing Fang, Xinqiao Jin, Bo Fan, Yonghua Zhu Jan 2014

The Evaluation Method Of Hvac System’S Operation Performance Based On Energy Flow Analysis And Dea, Xing Fang, Xinqiao Jin, Bo Fan, Yonghua Zhu

International Refrigeration and Air Conditioning Conference

An energy flow model of an airport terminal’s HVAC system is established in this paper. Based on energy flow model, the exergy efficiency, exergy loss and exergy cost distribution ratio of each component are calculated and analyzed by the energy flow model. Optimization method and exergy balance equations are used to calculate the least exergy loss of HVAC system under certain operation condition, which is defined as the near-optimum operation level. DEA method is then applied to obtain the benchmarking frontier of near-optimum operation levels, and the frontier will illustrate the ideal operation level under overall operation conditions. In order …

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Numerical And Experimental Analysis Of Heat And Mass Transfer Processes On Water Trays In Household Refrigerators, Adriano Francisco Ronzoni, Cláudio Melo, Carolin Ries Jan 2014

Numerical And Experimental Analysis Of Heat And Mass Transfer Processes On Water Trays In Household Refrigerators, Adriano Francisco Ronzoni, Cláudio Melo, Carolin Ries

International Refrigeration and Air Conditioning Conference

Frost formation on the cold evaporator surface is a typical problem in household refrigerators. It happens due to humidity present in the ambient air associated with frequent door openings. In addition, mass transfer from stored goods to dry internal cabinet air and moisture infiltration through door gaskets also contribute to frost formation on the evaporator surface. To prevent this, the evaporator has to be defrosted manually or automatically (as in modern refrigerators). To do so, an electrical heater is switched on at a preset time and frequency and defrosts the evaporator. During this time, defrosted water is drained through a …

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Shape Optimization Of A Compressor Supporting Plate Based On Vibration Modes, Olavo M. Silva, Thiago M. Guesser, Igor M. Guesser, Claudio De Pellegrini, Carlos E. Vendrami, Arcanjo Lenzi Jan 2014

Shape Optimization Of A Compressor Supporting Plate Based On Vibration Modes, Olavo M. Silva, Thiago M. Guesser, Igor M. Guesser, Claudio De Pellegrini, Carlos E. Vendrami, Arcanjo Lenzi

International Refrigeration and Air Conditioning Conference

In typical household refrigeration systems, the compressor is structurally connected to the cabinet through an assembly composed of rubber mounts and a steel support plate, usually called base-plate. This plate works as a vibration energy path from the compressor to other refrigerator components, and its dynamic behavior must be known in order to avoid the coincidence of resonances and operational frequencies , a situation in which the energy flow is maximized. One way to design a support that satisfies this requirement is to optimize the shape of the plate, locating its structural modes as far as possible from the operational …

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Virtual Power Consumption And Cooling Capacity Virtual Sensors For Rooftop Units, Howard Cheung, James E. Braun Jan 2014

Virtual Power Consumption And Cooling Capacity Virtual Sensors For Rooftop Units, Howard Cheung, James E. Braun

International Refrigeration and Air Conditioning Conference

Implementation of advanced controls and diagnostic features in small commercial buildings typically requires real-time monitoring of the energy flows, such as the power consumption and cooling capacity of rooftop units. However, these measurements are expensive and therefore limit the application of these advanced features. In order to lower the measurement cost, virtual sensing technology for rooftop unit power consumption and cooling capacity are being developed. Power transmitters and thermocouples are installed on the rooftop units to train the virtual sensors. The idea is to recycle the power transmitters after training to save cost, and then the virtual sensors estimate hourly …

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Numerical Model Of Capillary Tubes: Enhanced Performance And Study Of Non-Adiabatic Effects, Nicolas Ablanque, Carles Oliet, Joaquim Rigola, Carlos David Pérez-Segarra Jan 2014

Numerical Model Of Capillary Tubes: Enhanced Performance And Study Of Non-Adiabatic Effects, Nicolas Ablanque, Carles Oliet, Joaquim Rigola, Carlos David Pérez-Segarra

International Refrigeration and Air Conditioning Conference

In this work a numerical model to simulate the thermal and fluid-dynamic phenomena inside non-adiabatic capillary tubes is presented. The model presented herein is an improved version of the distributed model detailed in [1]. It is based on a pseudo-homogeneous two-phase flow model where the governing equations (continuity, momentum, energy and entropy) are integrated over the discretized fluid domain and solved by means of a step-by-step scheme. The main novelty of the improved algorithm is its enhanced capability to address many of the convergence issues typically found in distributed models as stated by [2] and [3]. In addition, the newest …

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Transient Exergy Destruction Analysis Of A Vapor Compression System, Neera Jain, Andrew Alleyne Jan 2014

Transient Exergy Destruction Analysis Of A Vapor Compression System, Neera Jain, Andrew Alleyne

International Refrigeration and Air Conditioning Conference

Through online optimization and control, vapor compression systems (VCSs) can effectively respond to disturbances, such as weather or varying loads that cannot be accounted for at the design stage, while simultaneously maximizing system efficiency. However, to do so requires a mathematical characterization of efficiency for the VCS. In particular, we would like to maximize the exergetic efficiency of the VCS which characterizes system efficiency relative to the maximum achievable efficiency as postulated by the second law of thermodynamics. This is equivalent to minimizing the rate of exergy destruction during system operation. Furthermore, in applications where VCSs encounter high frequency disturbances, …

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Structured Pairing In A First-Year Electrical And Computer Engineering Laboratory: The Effects On Student Retention, Attitudes, And Teamwork, Nicholas D. Fila, Michael C. Loui Jan 2014

Structured Pairing In A First-Year Electrical And Computer Engineering Laboratory: The Effects On Student Retention, Attitudes, And Teamwork, Nicholas D. Fila, Michael C. Loui

School of Engineering Education Graduate Student Series

This paper describes a simple technique, structured pairing, for organizing student teams in engineering instructional laboratories. This technique was adapted from pair programming, which was previously found to improve student confidence, satisfaction, and retention in computer science. A study of structured pairing was implemented in a large required course for first-year students in electrical and computer engineering. Six laboratory sections implemented structured pairing, and the other seven laboratory sections operated in a traditional way (i.e., unstructured team interactions). Data were collected from a student survey, two focus groups, and course enrollment records. Structured pairing students reported significantly higher confidence in …

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The Role Of Design Skills In Design Review Conversations: An Analysis Using The Multiple Intelligence Framework, Newton D'Souza, Kinkini Chandrasekhara Jan 2014

The Role Of Design Skills In Design Review Conversations: An Analysis Using The Multiple Intelligence Framework, Newton D'Souza, Kinkini Chandrasekhara

Design Thinking Research Symposium

Design skills are diverse abilities intentionally used by designers to achieve desired goals in specific design scenarios. However, very little is known about how design skills are manifested, expressed or encouraged in a design review conversation. This study uses the multiple intelligence framework to map and analyze design skills of four different review conversations by the interaction between instructor, student and the clients. The findings reveal that consistency and endurance in skill application is more critical than the frequency and duration of skill application for successful design outcomes. Moreover, skill diversity and alignment of student skill-set with instructor and client …

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Annual Performance Of A Solar Assisted Heat Pump Using Ice Slurry As A Latent Storage Material, Justin Tamasauskas, Michel Poirier, Radu Zmeureanu, Martin Kegel, Roberto Sunye Jan 2014

Annual Performance Of A Solar Assisted Heat Pump Using Ice Slurry As A Latent Storage Material, Justin Tamasauskas, Michel Poirier, Radu Zmeureanu, Martin Kegel, Roberto Sunye

International High Performance Buildings Conference

Solar assisted heat pump systems offer an attractive method of reducing the energy used for space heating and cooling, while efficiently using low temperature renewable energy from the sun to reduce the degradation of heat pump performance at low ambient temperatures. However, the majority of these systems use sensible storage to bridge the gap between thermal supply and demand, with the maximum storage capacity limited by physical constraints within the building. Latent storage has the potential to significantly reduce the required tank volumes in these types of systems. Previous work has demonstrated the benefit in heating mode of combining a …

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Influence Of Approaches In Cfd Solvers On Performance Prediction In Screw Compressors, Ahmed Kovacevic, Sham Rane, Nikola Stosic, Yu Jiang, Sam Lowry, Michal Furmanczyk Jan 2014

Influence Of Approaches In Cfd Solvers On Performance Prediction In Screw Compressors, Ahmed Kovacevic, Sham Rane, Nikola Stosic, Yu Jiang, Sam Lowry, Michal Furmanczyk

International Compressor Engineering Conference

Computational Fluid Dynamics (CFD) offers insight into screw compressor designs beyond the capabilities of other conventional methods. It allows evaluation of local flow patterns which influence performance but are difficult or impossible to investigate experimentally. Implementation of CFD in these machines is challenging due to the physics of the flow, the properties of the working fluids and the complexity of flow passages which change size and position. This is additionally challenged by a lack of methodologies available to generate the meshes required for the full three dimensional transient simulations. Commercially available CFD solvers need to fully interact with customized grid …

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Modelling And Simulation Of The Dynamics Of Cross Vane Expander-Compressor Unit For Vapour Compression Cycle, Ken Shaun Yap, Kim Tiow Ooi, Anutosh Chakraborty Jan 2014

Modelling And Simulation Of The Dynamics Of Cross Vane Expander-Compressor Unit For Vapour Compression Cycle, Ken Shaun Yap, Kim Tiow Ooi, Anutosh Chakraborty

International Compressor Engineering Conference

The Cross Vane mechanism was recently invented and employed in the design and development of an expander-compressor unit, named Cross Vane expander-compressor or CVEC in short. This device replaces the compressor and expansion valve of a conventional vapour compression cycle, and improves the energy efficiency of the system. Theoretical models which include geometrical, thermodynamics, mass flow, as well as mechanical loss models are developed to characterize the performance of CVEC. Numerical simulation was performed, and the results show that the device is capable of reducing the energy consumption and the peak power requirement of the refrigeration system. Energy saving and …

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Pd Compression: A Quasi-Static Or Dynamic Process?, Paul Xiubao Huang Jan 2014

Pd Compression: A Quasi-Static Or Dynamic Process?, Paul Xiubao Huang

International Compressor Engineering Conference

Gas compression in a positive displacement (PD) type piston engine, or piston compressor, has long been modeled as a quasi-static process in which the piston is assumed to move infinitely slow inside a cylinder. The gas compression mechanism is therefore regarded as being governed by the basic thermodynamic principles. Energy transfer is accomplished quasi-statically with a piston reducing the volume a little at a time, small perturbation, while increasing gas pressure simultaneously. This is in direct contrast to a dynamic type gas compressor such as turbo compressor that achieves energy transfer by initially imparting kinetic energy to the gas and …

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Development And Validation Of Integrated Design Framework For Compressor System Model, Parag Mantri, Aditya Bhakta, Srinivas Mallampalli, Greg Hahn, Srujan Kusumba Jan 2014

Development And Validation Of Integrated Design Framework For Compressor System Model, Parag Mantri, Aditya Bhakta, Srinivas Mallampalli, Greg Hahn, Srujan Kusumba

International Compressor Engineering Conference

The performance of a refrigerator is largely guided by the efficiency of its drive unit, namely, the compressor & understanding the compressor behavior requires a detailed study of its dynamics, flow-thermals, electrical and controls aspects. Having a simulation model which captures these physics reasonably well is a critical part of the design and performance prediction of a compressor. The current paper describes a systematic approach of making a system level simulation framework by first developing individual models and then integrating them into a single framework to capture the multi-physics interaction of the different sub-components. This framework, developed in MATLAB/SIMULINK contains …

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